Financial engineering - one of the core elements in the business model of private equity funds is under pressure. Increasing tax legislation has removed the majority of the tax shield that the funds have benefited from earlier and moreover the current situation has frozen the financial markets and thereby eliminated or at least decreased the option of gearing the portfolio companies. In light of this we decided to analyze four pillars of the business model, which we believe are the most important; Financial, Governance, Operational and Strategic Engineering. The analysis was built on two cases, one already exited and one still ongoing. This was done in order to address the effect of the timing, while the number of cases was held to a minimum to ensure that the case study was able to go into depth with the engineering applied in the two cases. This was combined with an outlook into likely developments that will influence and change the business environment that the private equity firms operate in. It is essential that the PE firms adapt to changes in the business environment, in order for the business model to be viable in the future.